This invention relates to transferring whole core samples, e.g., for handling and transport. More particularly, the present invention relates to apparatus and methods for transferring whole core samples which promote the preservation of the samples in the "as obtained" state.
Core samples obtained from subterranean formations are often used to assist in determining the commercial potential, e.g., commercial petroleum producing potential, of such formations. Since detailed analysis of these core samples frequently occurs away from the sampling site, it is necessary to transport the samples for analysis. The most useful analysis of such cores are obtained if the samples are maintained in the "as obtained" state or condition. A number of methods have been used to preserve such core samples in the "as obtained" condition.
Unconsolidated and other friable core samples are generally frozen to reduce grain rearrangement during handling and transportation. However, freezing may alter the rock sample. When freezing is suspected of altering the rock sample, another method of preservation is used. Most of these other methods involve encapsulation of the core in wax or epoxy resin. The potential for imbibition of such materials into the sample is of concern. In addition, if further shrinkage of the sample should occur, e.g., during transportation, the rigid walls of the solidified encapsulating material provides limited, if any, support for the rock sample so that the sample may fall apart. A new system overcoming these concerns and problems would clearly be advantageous.
The technical literature has described the confinement of plugs with heat shrink tubing. However, such tubing is not believed to have been used on whole core samples during confinement.